This research will involve patients who have just been diagnosed with cancer of the head and neck. Radiation therapy has been recommended to treat this disease. Radiation therapy is a form of cancer treatment using high energy x-rays. One of the possible effects of radiation therapy is a significant and permanent lessening of normal mouth moisture. Although there are medications to treat dry mouth (caused by irradiated salivary gland) after radiation therapy, it might be better to protect the salivary gland during the radiation. Another side effect of radiation therapy given to the head and neck region is sores in the mouth. This condition (radiation mucositis), can produce significant redness and painful ulcers. These interfere with talking and eating for a period of several weeks during the radiation. Previous, but as yet unproved, studies have shown that both dry mouth and radiation mucositis may be lessened by taking pilocarpine hydrochloride pills just before and during the radiation therapy. So far, pilocarpine hydrochloride (Salagen) is an approved drug for treating dry mouth after radiation therapy to the head and neck. This study will see whether oral pilocarpine for three months, including during radiation, will be able to: 1) reduce the expected radiation mucositis and 2, preserve oral moisture by protecting the salivary gland during the radiation therapy.